From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=90.155.50.34 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793802740; b=ag4rKIi/7eLaYvqOl+rn27tY/HsTt7q1xSWxw6sAGz+L5FE8UCOlwtt0jp4jQX2DB6Ht WxxiGJq3g2/Z/4K2rKBuf1LugSyHjImuiwtV8KXC2SfpHWm8RRmgJ8rnvI1jKZgnjIb7/ jnFpE6QvvkGWf34rs2Gj9KzWncNPtoFZAesRraKFTg7xXr/Zs5dcxVBCWDL7ULG+sGG4y ZHuXr1ZxRyAlcBfPLOj5VRRaOiIqGjHrlzPwv+TWDTpDDnRXNjXmFmBXX28mSXIxUJgul fMeZKKCUA5ahO0O6Exy+UbfxxDkBl9+M1WGgfgAFAQ0j515EoqQ3gm0B2pbF/KADtyA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793802740; h=DMARC-Filter:DKIM-Signature:Received:Date:From:To:Cc:Subject: Message-ID:References:MIME-Version:Content-Type:Content-Disposition: In-Reply-To; bh=ruu8JrnBwogLTne/D6uuGsufWUgVImMj+eWmulfcz+E=; b=RMSW4ogePJdt5aLCe+UwtRS41mxUGyMLbKxcDXmzs8G+IHkyPcwovnTHm+w8OCl2nxoE WDR5pAfZV1HwhNw/SjCeVCRRb+t7aB4G7iF8CO/noN0ncZ8CHMM6IWLWT0h05G1Ld49mH ARmJJAFaAJu8aSBPRbWDbzQqXJms+q4oPQKbgITdZhWl7z42wUJw6W/C3Mp5GZV+3BI7T wXwMVmzbohl984L2acAZP6/tKnHV2vYn6aUZtTqxKcGNDn31FXFPH+N0ZQwPFS8RfdPfM NQYytYa3YUnXmiwhyh5sEkDvQSBvE31Zn8/6R5pij1bMWmQazkhifq/JvenlZqaDzYA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=infradead.org; spf=pass smtp.mailfrom=infradead.org; dkim=pass header.d=infradead.org header.i=@infradead.org header.a=rsa-sha256 header.s=casper.20170209 header.b=WPShMz71; arc=none smtp.remote-ip=90.155.50.34 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 16746606A31B; Wed, 4 Nov 2026 14:32:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 16746606A31B Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=infradead.org header.i=@infradead.org header.a=rsa-sha256 header.s=casper.20170209 header.b=WPShMz71 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=ruu8JrnBwogLTne/D6uuGsufWUgVImMj+eWmulfcz+E=; b=WPShMz71Ub0ru03Q+/16XtsIp3 hFwUkwg6C46KgyjigFTJ3sWDX+t8VOtxv9XebZasMzS/SEqjE5XsuSQHHqOo+SVtNX7qrmmNd1D44 w0HDiJiRJUKPqPXx3LYdBvWmk+tJfvWU0L1DmaJbPdiQQGpm11EWCRDRo6dz4WdfEcKaV8kLvD3Ib s78Yn32GD37QQrlisZD4u+EHy629/zWbdwVy8IlFBOgeF6u0/eUl4gHkAjbWRUoS1+iLt0ebNvuv/ E+0MDABf8vf5iLPZfw7+vpeSTCghHpivz48qTgyV9lwHZbh4CPQUHe2XtlYS01Wll2Qjmgji8JMZ3 5DAPZMsQ==; Received: from willy by casper.infradead.org with local (Exim 4.100.1 #2 (Red Hat Linux)) id 1xOc2C-00000009glu-2ihC; Wed, 04 Nov 2026 14:32:16 +0000 Date: Wed, 4 Nov 2026 14:32:16 +0000 From: Matthew Wilcox To: Hungyu Lin Cc: me@bobcopeland.com, akpm@linux-foundation.org, linux-karma-devel@lists.sourceforge.net, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] omfs: reject writes starting beyond EOF Message-ID: References: <20261104112052.5604-1-dennylin0707@gmail.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261104112052.5604-1-dennylin0707@gmail.com> On Wed, Nov 04, 2026 at 11:20:52AM +0000, Hungyu Lin wrote: > OMFS does not initialize gaps between EOF and a buffered write. When the > requested block lies beyond the allocated extents, omfs_get_block() grows > the last extent and maps the write to the newly allocated block without > accounting for the skipped logical blocks. > > A one-byte pwrite() at offset 8192 into an empty file returns success, as > does fsync(), but after remounting the byte is at offset 0 and offset 8192 > reads as zero. > > Reject writes starting beyond i_size before block_write_begin() can > allocate or map buffers. Overwrites, appends and writes crossing EOF > remain allowed. Gap initialization can be implemented separately. Why don't we just delete omfs? This is the proprietary file system used by the Rio Karma music player and ReplayTV DVR Rio Karma and ReplayTV were both EOL in 2005. Let's just delete this filesystem.